Botany 2021 Paper I 50 marks Compare and contrast

Q8

(a) Compare and contrast 'preservation' and 'conservation' of plants. Explain the importance of both in the utilization and management of plant resources. (20 marks) (b) Describe different stages of micropropagation and discuss its advantages over conventional methods of propagation. (20 marks) (c) Explain the technique used in producing androgenic haploids and its applications in agriculture. (10 marks)

हिंदी में प्रश्न पढ़ें

(a) पादपों के 'परिरक्षण' एवं 'संरक्षण' की तुलना एवं विषमता कीजिए। पादप साधनों की उपयोगिता एवं प्रबंधन में दोनों का महत्व समझाइए। (20 अंक) (b) सूक्ष्म-प्रवर्धन की विभिन्न अवस्थाओं का वर्णन कीजिए और परम्परागत प्रवर्धन विधियों की तुलना में इसकी श्रेष्ठता की विवेचना कीजिए। (20 अंक) (c) पुंजनिक अगुणित प्राप्ति की तकनीक एवं कृषि में इसकी उपयोगिता का वर्णन कीजिए। (10 अंक)

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Directive word: Compare and contrast

This question asks you to compare and contrast. The directive word signals the depth of analysis expected, the structure of your answer, and the weight of evidence you must bring.

See our UPSC directive words guide for a full breakdown of how to respond to each command word.

How this answer will be evaluated

Approach

Begin with a brief introduction linking plant resource management to food security and biodiversity. For part (a), spend ~40% time (8-10 minutes) establishing clear definitional boundaries between preservation (static, ex-situ) and conservation (dynamic, in-situ with sustainable use), then explain their complementary roles in germplasm management. For part (b), allocate ~35% time (7-8 minutes) describing the five stages of micropropagation with a flow diagram, contrasting with seed/vegetative propagation. For part (c), use remaining ~25% time (5-6 minutes) detailing anther/pollen culture protocols and agricultural applications like rapid homozygous line development. Conclude with integrated remarks on biotechnology's role in conservation.

Key points expected

  • Part (a): Distinction between preservation (maintenance of genetic material in unchanged state, ex-situ) vs conservation (protection and sustainable use of natural populations, in-situ); their complementary importance in germplasm utilization and resource management
  • Part (a): Importance in utilization: preservation ensures genetic erosion prevention for future breeding, conservation maintains ecosystem services and evolutionary potential; management through gene banks, botanical gardens, protected areas, and community reserves
  • Part (b): Five stages of micropropagation: (i) selection and surface sterilization of explant, (ii) initiation/establishment of aseptic culture, (iii) multiplication/shoot proliferation, (iv) rooting/in vitro rooting, (v) hardening and acclimatization
  • Part (b): Advantages over conventional propagation: clonal fidelity, rapid multiplication rate, disease-free stock production, season-independent production, conservation of rare/endangered species, and space efficiency in commercial horticulture
  • Part (c): Androgenic haploid production techniques: anther culture (in situ anthers on nutrient medium) and isolated microspore culture; pretreatments (cold/heat shock, starvation); embryogenesis pathway from microspores to haploid embryos
  • Part (c): Applications: instant homozygosity through chromosome doubling for pure line development, mutation breeding, genetic mapping, QTL identification, and hybrid seed production (e.g., rice, wheat, maize, Brassica improvement programs at IRRI and IARI)

Evaluation rubric

DimensionWeightMax marksExcellentAveragePoor
Concept correctness22%11Precisely distinguishes preservation (static, ex-situ maintenance) from conservation (dynamic, sustainable use); correctly identifies five micropropagation stages in sequence; accurately describes androgenic pathway (microspore embryogenesis vs callus route) with correct ploidy levelsBasic distinction between terms present but blurred boundaries; stages of micropropagation listed with minor sequence errors; androgenic technique mentioned but confused with gynogenesis or ploidy status unclearTerms used interchangeably without distinction; micropropagation stages missing or jumbled; fundamental errors in describing haploid production mechanism or ploidy relationships
Diagram / labelling18%9Clear flow diagram for micropropagation stages with labelled arrows showing culture media transitions; schematic of anther culture showing locule, microspores, and embryo development; proper use of scientific symbols and scale indicatorsSimple block diagram for micropropagation without medium specifications; basic anther cross-section without developmental stages; adequate labelling but missing critical annotationsNo diagrams despite clear visual demand; or diagrams copied without relevance; poor labelling making interpretation impossible
Examples & nomenclature18%9Cites Indian examples: NBPGR (National Bureau of Plant Genetic Resources) for preservation; cardamom, banana, teak micropropagation at NRCB/NBRI; rice anther culture at CRRI Cuttack; mentions specific media (MS medium, N6 medium) and growth regulators (2,4-D, BAP, NAA) with concentrationsGeneric examples without Indian specificity; mentions MS medium but no modifications; standard hormone names without application contextNo institutional or species-specific examples; incorrect media names; confused hormone applications or missing nomenclature entirely
Process explanation22%11Detailed sequential explanation: for micropropagation—surface sterilization protocol (HgCl2/ethanol concentrations, duration), multiplication mathematics (multiplication factor calculations), hardening humidity gradients; for androgenesis—pretreatment rationale, starvation/nitrogen stress mechanism, chromosome doubling methods (colchicine treatment)Stages described in order but lacking technical depth; basic mention of sterilization and hardening; androgenesis process outlined without pretreatment details or doubling mechanismProcesses described as lists without causal mechanisms; critical steps omitted; confused explanation suggesting misunderstanding of in vitro vs in vivo conditions
Application / ecology20%10Integrates applications: preservation for Vavilovian centers of diversity (Hindu Kush-Himalayan region); conservation for biosphere reserves (Nilgiri, Nanda Devi); micropropagation for virus elimination (meristem culture) and endangered species recovery (Red sanders, Nepenthes khasiana); androgenic haploids for CMS line development in hybrid rice (China, India)Mentions general applications without specific conservation programs; standard horticultural uses of micropropagation; basic breeding application of haploids without crop-specific examplesApplications generic or missing; no linkage to Indian agricultural context; ecological significance ignored; fails to connect techniques to sustainable development goals

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